In a short statement Wednesday the EU Council President Donald Tusk said a short extension was possible but was "conditional on a positive vote in the House of Commons."
Adding that the EU would not give up on apolitical solution "until the last moment," Tusk said he did not see any need at this point for an emergency EU summit but it was possible.
That followed comments from the EU's chief Brexit negotiator Michel Barnier who said Tuesday that Europe must protect itself when considering a Brexit extension. At the forefront of the EU's concerns is preventing any disruption to European parliamentary elections between May 23-26.
Berenberg's Schmieding said that the EU27 being "exasperated" with the U.K.'s dithering on Brexit was "understatement of the year." Still, the EU wants to avoid a "hard" Brexit (where no trade relationship with Britain is in place) and doesn't want to be blamed for causing a "no-deal" Brexit.
That means that the EU could either endorse the U.K.'s request for a delay in principle on Thursday, or that EU could ask the U.K. to specify by 28 or 29 March "whether it wants to use the delay simply to finalize and ratify one of the three easy Brexit options, namely May's deal, an augmented customs union or full single market membership," Schmieding said.
"The EU could then call a special summit at short notice to formally grant the Brexit delay request," he noted.
If the U.K. said that it wanted a customs union or full single market membership this would require only limited changes, if any, to the Brexit deal (or 'Withdrawal Agreement', as it's officially known). But if the U.K. cannot endorse one of the three options on the table by 28 March, the delay would have to be much longer, Schmieding said.